I thought about mentioning the Walker II and III radios, but the Taylor was around the same price as a cobra 29.
Hard to put a number on it, depending on where your RF gain is set, you maybe looking around a mile. The bad part about running the RF gain lower is that it will effect the radios S/RF signal meter. So if someone a couple of miles away is talking you won't know it because the meters needle won't move.
Well it's hard to say, it depends on the other guys setup. Unfortunately trucks today aren't cb friendly. Because of that most radios might reach out 3 or 4 miles. With a proper antenna system and band conditions, most cb radios can talk 5 to 10 miles. Usually you lower the RF gain on your radio while sitting at the truck stop when another driver is talking so his signal doesn't overload your radios receiver. Just wondering why you want to run the RF gain lower?
Oh okay, personally I've always just raised the squelch just enough to cut out the static and weak signals. I guess to really answer your question on distance, the only way to know would be to run down the road with a buddy, and when his signal cuts out (RF gain at 50%) then find out what mile marker he's at. I guess that would give you a rough idea how far apart you are.
Another really good radio is the Anytone 6666 Pro. It has automatic squelch, a hi-cut filter that reduced white noise, a DSP board that cuts out a lot of noise, and a built-in NPC circuit.